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doc.: IEEE 802.22-13-0012-00-000b Submission Jan 2013 PHY Comparison between NICT proposal (22-12-0090- 03-000b) and the legacy 802.22 IEEE P802.22b Wireless RANs Date: 2013-1-05 Authors: Notice: This document has been prepared to assist IEEE 802.22. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.22. Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures http://standards.ieee.org/guides/bylaws/sb-bylaws.pdf including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chairhttp://standards.ieee.org/guides/bylaws/sb-bylaws.pdf Wendong HuWendong Hu as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.22 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at patcom@iee.org.patcom@iee.org Slide 1
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doc.: IEEE 802.22-13-0012-00-000b Submission Abstract This contribution serves the purpose of comparing the legacy 802.22 PHY with the proposed PHY (22-12- 0090-03-000b), hence a better understanding of the proposal (22-12-0090-03-000b) is achieved. Jan 2013 Slide 2
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doc.: IEEE 802.22-13-0012-00-000b Submission 1.General (corresponding to section 9.1) 2.Frame Structure (corresponding to section 9.4) 3.OFDM subcarrier allocation (corresponding to section 9.6) 4.Channel Coding (corresponding to section 9.7) Compared PHY Items Jan 2013
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doc.: IEEE 802.22-13-0012-00-000b Submission 1. General 802.22 PHYProposed PHY Duplex modeTDD Multiplex modeOFDMA FFT size20481024 Sampling frequency6.8575.600MHz Sampling period145.833178.571usec Carrier spacing3.3485.469kHz Useful symbol period298.667182.857usec Cyclic prefix (1/32)9.3335.714usec Total symbol period308.000188.571usec Number of null carriers (L, DC, R)368 192 carriers Downstream 184Upstream Number of used carriers1680 832 carriers Downstream 840Upstream Occupied bandwidth5.625 4.55 MHz Downstream 4.594Upstream Lower channel edge guardband188.3 726.4 kHz Downstream 704.4 Upstream Upper channel edge guardband186.7 723.6 kHz Downstream 701.6 Upstream Jan 2013
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doc.: IEEE 802.22-13-0012-00-000b Submission Preamble: different (slide 7) Control header and MAP definitions: different (Details will be presented in the upcoming session) 2. Frame Structures Jan 2013
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doc.: IEEE 802.22-13-0012-00-000b Submission Example of Proposed OFDMA frame sub-channel (4tiles) 7 symbol 4 symbol Jan 2013
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doc.: IEEE 802.22-13-0012-00-000b Submission Preamble Proposed PHY –Preamble are defined using equation: –where PreambleCarrierSetn specifies all sub-carriers allocated to the specific preamble n is the designating number of the preamble carrier-set indexed 0, 1, and 2. k is a running index. 0-567 for 2K-FFT, 0-283 for 1024-FFT, 0-142 for 512-FFT, and 0-35 for 128-FFT. 802.22 PHY 1) Short Training Sequence (STS): 2) Long Training Sequence (LTS): –The STS is used to form the superframe and CBP preambles while the LTS is used to form the frame preamble. PreambleCarrierSetn = n + 3k Jan 2013
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doc.: IEEE 802.22-13-0012-00-000b Submission Data Mapping (Downstream) Legacy 802.22 PHY – One slot is defined as one sub-channel (28 sub-carriers) by one OFDM symbol. – Null and pilot subcarriers are assigned first. – 1440 complex data are interleaved then assign to the remaining sub- carrier. Proposed PHY – One slot is defined as one sub-channel by four OFDM symbol. – Fit data into one slot, then go down on sub-channel number, and followed by OFDM symbol Jan 2013
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doc.: IEEE 802.22-13-0012-00-000b Submission Jan 2013 Slide 9 OFDM symbol Subchannel 1-Subchannel DS (The legacy.22) 1-Subchannel 1 tile for DL Proposed PHY
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doc.: IEEE 802.22-13-0012-00-000b Submission Data Mapping (Upstream) Legacy 802.22 PHY – One slot is defined as one sub-channel (28 sub-carriers) by one OFDM symbol – They are first mapped horizontally, OFDM symbol by OFDM symbol (or at least 7 OFDM symbol at a time), in the same logical sub-channel. – Once the logical sub-channel is fully filled, data shall be mapped to the next logical sub-channel in an increasing order. Proposed PHY – One slot is defined as one sub-channel by seven OFDM symbol – Data is fitted into one slot first, – The allocation shall be continued by increasing OFDM symbol, then followed by increasing sub-channel number. Jan 2013
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doc.: IEEE 802.22-13-0012-00-000b Submission Jan 2013 Slide 11 1-Subchannel OFDM symbol Subchannel US The legacy.22 1 tile for UL 1-Subchannel The proposed PHY
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doc.: IEEE 802.22-13-0012-00-000b Submission Pilot Pattern: different (slide 11) DS and US Subcarrier Allocation: different (slide 12) 3. OFDM subcarrier allocation Jan 2013
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doc.: IEEE 802.22-13-0012-00-000b Submission Pilot Pattern OFDM symbol Sub-channel Data Subcarrier Pilot Subcarrier 802.22 Pilot PatternProposed Pilot Pattern Downstream Upstream
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doc.: IEEE 802.22-13-0012-00-000b Submission Subcarrier Allocation in Proposed PHY ParametersDownstream(DS)Upstream(US)Notes Number of DC subcarriers 11— Nused833841 Number of all subcarriers used within a symbol Number of Guard Subcarriers: left, right 96, 9592, 91— Tile Permutation {6, 48, 37, 21, 31, 40, 42, 32, 47, 30, 33, 18, 10, 15, 50, 51, 46, 23, 45, 16, 39, 35, 7, 25, 11, 22, 38, 28, 19, 17, 3, 27, 12, 29, 26, 5, 41, 49, 44, 9, 8, 1, 13, 36, 14, 43, 2, 20, 24, 4, 34, 0} {33, 52, 35, 67,94, 13, 80, 6, 34, 45, 43, 68, 84, 66, 7, 37, 71, 89, 55, 101, 27, 60, 51, 14, 21, 17, 93, 72, 95, 73, 81, 24, 103, 86, 39, 29, 56, 62, 70, 64, 23, 22, 54, 15, 90, 76, 100, 3, 36, 18, 9, 91, 19, 26, 12, 92, 48, 25, 87, 74, 5, 31, 85, 40, 104, 2, 102, 69, 57, 50, 1, 44, 0, 20, 88, 79, 16, 28, 46, 42, 41, 59, 96, 97, 99, 82, 30, 49, 65, 77, 63, 11, 8, 75, 98, 38, 32, 83, 4, 47, 58, 61, 78, 10, 53} Used to allocate tiles to subchannels Nsubchannels52105 — Ntiles208210— Number of subcarriers per tile 44 Number of all subcarriers used within tile Tiles per subchannel42 — Jan 2013
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doc.: IEEE 802.22-13-0012-00-000b Submission Process: almost the same Data scrambling scheme: same FEC: same convolutional coding (mandatory) Puncturing : same Bit-interleaver: different (slide13) Modulation and Code Rate: same QPSK, 16QAM, 64QAM Code Rate: 1/2, 2/3, 3/4, 5/6 4. Channel Coding Data scrambler FEC Bit- Interleaver Modulation (constellation mapping) Repetition Repetition coding can be applied in the proposed PHY Jan 2013
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doc.: IEEE 802.22-13-0012-00-000b Submission 802.22 PHY Turbo-Like Interleaving (TLI) algorithm Proposed PHY Two times permutation is performed Bit-interleaving The first permutation is defined by m k = (N cbps ⁄ d) ⋅ k mod(d) + floor(k ⁄ d) k = 0, 1, …, N cbps – 1, d = 18 The second permutation is defined by j k =s ⋅ floor(m k ⁄ s) (m k + N cbps – floor(d ⋅ m k ⁄ N cbps )) mod(s) k = 0, 1, …, N cbps – 1, d = 18 Jan 2013
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doc.: IEEE 802.22-13-0012-00-000b Submission Conclusion In this contribution, Several aspects of PHY between the legacy 802.22 and the proposal (22-12-0090-03- 000b) are compared. They are: –General –Frame Structure –Preamble –Data Mapping –Pilot assignment –OFDM subcarrier allocation –Bit Interleaving Slide 17 Jan 2013
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doc.: IEEE 802.22-13-0012-00-000b Submission Reference IEEE std 802.22-2011 Slide 18 Jan 2013
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